Large information handling system installations, such as data centers, server farms, and telecommunications switching systems (all referred to hereinafter generically as “data centers”) generate a great deal of waste heat that must be dissipated in order for the systems to continue operation. The capacity of such data centers continues to grow at a rapid pace to meet the demands of an increasingly “wired” society. Not only are such installations steadily increasing in computing capacity and overall volume, their power density is also increasing. Greater size and density, naturally, leads to greater or improved cooling requirements.
Conventional data center cooling systems typically include a cool air supply provided by air conditioning systems. Cool air from the air conditioner is routed through a plenum formed by a raised floor upon which data center cabinet-enclosed rack-mounted computing or switching components rest. Cool air passes from the plenum into the cabinets and, as much as possible, through the components that require cooling for a forced convective flow of heat away from the components. The air heated by the components is then supposed to return to the air conditioner to be cooled and re-circulated through the raised floor plenum and through the electronic components in need of cooling. Some systems are more effective than others. For example, in many installations air warmed by the components finds its way back to the components before returning to be cooled by the air conditioning system. In this way, cooling air is mixed with air warmed by the components. This mixture of warm and cool air is much less effective at cooling the components. In fact, some estimates indicate that as much as 70% of cool air generated in a data center does not make contact with the equipment to be cooled. In this way, a great deal of the energy is wasted by producing cooling air that isn't utilized effectively.
One way to improve the efficiency of data center cooling systems is to provide a system whereby cool air is supplied to equipment cabinets through a relatively closed system, such as a plenum formed by a raised floor, and the resultant, heated air, is returned to the air conditioner through duct-work either directly or through another plenum formed by a dropped ceiling. Although such a configuration provides improved efficiency compared to more conventional “open return” systems, such a system, in itself, does not address all the requirements for a modern data center cooling system. For example, one or more fans may be required to propel the heated, “waste air” back through a return duct and return plenum formed by the dropped ceiling to the air conditioning unit. The location, control, and maintenance of such fans has been approached in a somewhat haphazard fashion in some systems. A system and method that provides for efficient operation, ready maintenance and monitoring would therefore be highly desirable.